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authorTimothy Arceri <[email protected]>2017-01-12 17:01:03 +1100
committerTimothy Arceri <[email protected]>2017-04-24 12:08:14 +1000
commit83f7fdf83a0546e477aba7fb3685cf78588ea2be (patch)
treee1297a8971f8c45b61473f13e9454573d788c5e9
parent18947fde7ad60859ca1e843aaacf4f5db3c72b91 (diff)
nir: add flt comparision simplification
Didn't turn out as useful as I'd hoped, but it will help alot more on i965 by reducing regressions when we drop brw_do_channel_expressions() and brw_do_vector_splitting(). I'm not sure how much sense 'is_not_used_by_conditional' makes on platforms other than i965 but since this is a new opt it at least won't do any harm. shader-db BDW: total instructions in shared programs: 13029581 -> 13029415 (-0.00%) instructions in affected programs: 15268 -> 15102 (-1.09%) helped: 86 HURT: 0 total cycles in shared programs: 247038346 -> 247036198 (-0.00%) cycles in affected programs: 692634 -> 690486 (-0.31%) helped: 183 HURT: 27 Reviewed-by: Elie Tournier <[email protected]> Reviewed-by: Kenneth Graunke <[email protected]>
-rw-r--r--src/compiler/nir/nir_opt_algebraic.py4
-rw-r--r--src/compiler/nir/nir_search_helpers.h15
2 files changed, 19 insertions, 0 deletions
diff --git a/src/compiler/nir/nir_opt_algebraic.py b/src/compiler/nir/nir_opt_algebraic.py
index 49c1460e25a..bd65eff8b59 100644
--- a/src/compiler/nir/nir_opt_algebraic.py
+++ b/src/compiler/nir/nir_opt_algebraic.py
@@ -158,6 +158,10 @@ optimizations = [
# a != 0.0
(('flt', 0.0, ('fabs', a)), ('fne', a, 0.0)),
+ # ignore this opt when the result is used by a bcsel or if so we can make
+ # use of conditional modifiers on supported hardware.
+ (('flt(is_not_used_by_conditional)', ('fadd(is_used_once)', a, ('fneg', b)), 0.0), ('flt', a, b)),
+
(('fge', ('fneg', ('fabs', a)), 0.0), ('feq', a, 0.0)),
(('bcsel', ('flt', b, a), b, a), ('fmin', a, b)),
(('bcsel', ('flt', a, b), b, a), ('fmax', a, b)),
diff --git a/src/compiler/nir/nir_search_helpers.h b/src/compiler/nir/nir_search_helpers.h
index faa3bdfd12b..7decf6582a7 100644
--- a/src/compiler/nir/nir_search_helpers.h
+++ b/src/compiler/nir/nir_search_helpers.h
@@ -158,4 +158,19 @@ is_not_used_by_if(nir_alu_instr *instr)
return list_empty(&instr->dest.dest.ssa.if_uses);
}
+static inline bool
+is_not_used_by_conditional(nir_alu_instr *instr)
+{
+ if (!is_not_used_by_if(instr))
+ return false;
+
+ nir_foreach_use(use, &instr->dest.dest.ssa) {
+ if (use->parent_instr->type == nir_instr_type_alu &&
+ nir_instr_as_alu(use->parent_instr)->op == nir_op_bcsel)
+ return false;
+ }
+
+ return true;
+}
+
#endif /* _NIR_SEARCH_ */